# NTSB MIA02LA029: Hughes OH-6A, N129BC, Hernando, MS, November 25, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 25, 2001, 16:00 local (22:00 UTC) - Place: Hernando, MS - Coordinates: 34.820716, -89.980514 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.8207&lon=-89.9805&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 20, 2002 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 53840 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA02LA029 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53840/pdf - Page: https://openairdocs.org/ntsb/MIA02LA029 ## Probable cause The flight instructor's improper supervision of the dual student during a practice autorotation landing by allowing an excessive aft pitch attitude and low main rotor rpm conditions to develop during the landing/flare touchdown, which resulted in the helicopter making a hard landing on the heels of the skids, and the main rotor severing the tail boom. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - supervision - inadequate, pilot in command(cfi) (cause) - autorotation - performed, flightcrew - cyclic - excessive, dual student (cause) - rotor rpm - low, flightcrew (cause) - rotor system,main rotor - blade strike ## Analysis The flight instructor stated that he and the dual student were performing autorotations, and the student flared the helicopter at an altitude of about 65 feet, and applied initial collective pitch control input at about 10 feet, leveling the helicopter. The instructor said that the aircraft was about 2 feet high, and still moving forward, and at that point the student did not let the helicopter settle to the ground, but continued to apply collective pitch control input. He said he stopped the student from applying collective pitch control input and the aircraft descended, but during the descent the student applied aft cyclic control input, causing the aircraft to hit on the heels of the skids, while rotor rpms were low. The instructor said, that as a result, the main rotor blades contacted the tail boom, severing the tail just forward of the tail rotor gear box. ## Factual narrative On November 25, 2001, about 1600 central standard time, a Hughes OH-6A helicopter, N129BC, registered to, and operated by the Desoto County Sheriff's Office, as Title 14 CFR Part 91 instructional flight, made a hard landing at a private field in Hernando, Mississippi. Visual meteorological conditions prevailed, and no flight plan was filed. The student pilot, and the airline transport-rated flight instructor were not injured, and the helicopter incurred substantial damage. The flight originated from Hernando, Mississippi, the same day, about 1610. The flight instructor stated that they had been practicing autorotations and during the last autorotation the student was flying the helicopter. The instructor said that the airspeed on final was 70 knots, and that the student flared the helicopter at an altitude of about 65 feet, and applied initial collective pitch control input at about 10 feet, leveling the helicopter. He said that the helicopter was about 2 feet high, and still moving forward, and at that point the student did not let the helicopter settle to the ground, but continued to apply collective pitch control input. The instructor said he stopped the student from applying collective pitch control input, and the helicopter started to descend, but the student applied aft cyclic control input, and the helicopter contacted the ground on the heels of the skids, while main rotor rpms were low. He said the main rotor blades contacted the tail boom, severing the tail just forward of the tail rotor gear box. According to the flight instructor, prior to the accident, there were no failures or malfunctions to the helicopter, or any of its systems. ## Aircraft - Registration: [N129BC](https://openairdocs.org/deregistered/N129BC-2016-11-18), registration cancelled 2016-11-18, S/N 67-16214, built 1968 (OpenAirDocs) - Reported make and model: Hughes OH-6A - Registry model: [Hughes OH-6A](https://openairdocs.org/model/hughes-oh-6a) (registry code 4470905) (OpenAirDocs) - Registry engine: [Allison 250 SER 317HP](https://openairdocs.org/engine/allison-250-ser-317hp) (registry code 03011, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 67-1B214 - Airframe hours: 4129 - Engines: Allison 250-C10D 270 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Desoto County Sheriffs Department - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 5, 2001, 21 hours before - Departed: Hernando, MS - Airport: Fergussons private strip ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 53; injuries: none; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--no waivers/lim.; last flight review January 15, 2001; seat: left; flight hours: 11,000 total, 1,200 in this make and model, 8,900 as pilot in command, 95 in the last 90 days, 30 in the last 30 days, 3 in the last 24 hours - Student pilot; age 56; injuries: none; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review October 17, 2000; seat: right; flight hours: 520 total, 90 in this make and model, 300 as pilot in command, 27 in the last 90 days, 12 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 39 °F - Altimeter: 30.05 inHg - Observed at: MEM, 25 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20011125031789A](https://openairdocs.org/incident/20011125031789A), Nov 25, 2001: Hughes OH6A, Hernando, MS, Substantial damage. (-23) During auto rotation to ground, instructor pilot noticed aircraft descending too rapidly but could not recover in time. (.4) on November 25, 2001, about… ## Other investigations on N129BC (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB MIA95TA188](https://openairdocs.org/ntsb/MIA95TA188), Jul 21, 1995: McDonnell Douglas H369 (N129BC), Panama City, FL, substantial damage. Probable cause: The pilot-in-command's improper aft application of cyclic control during a simulated touchdown autorotation on landing flare touchdown, resulting in the main rotor blades colliding with the tail boom… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.